The present invention relates to an exposure method used during a fine pattern formation step in a manufacturing process of a substrate that forms a picture display unit of a flat panel display. The present invention further relates to an optical exposure method and exposure apparatus that uses the manufacturing method.
During a process for manufacturing a substrate used as a flat panel display, such as a liquid crystal display or a plasma display, when forming a fine pattern on the substrate, photolithography is normally implemented. Photolithography forms a preferable pattern shape on the substrate by forming a photosensitive film (photoresist) on the surface of the substrate and performing an exposure step for exposing the substrate with exposure light having a light distribution that is in accordance with the shape of a pattern that is to be formed. Then, a development step, an etching step, and the like are performed.
In the prior art, in the above exposure step performed during the manufacturing process of a flat panel display substrate, a mask is mainly used in the exposure method.
The pattern that is to be formed on the substrate is formed on the mask. Then, the mask is illuminated with illumination light. The light distribution transmitted through the mask is exposed on the substrate to transfer the mask.
As an exposure apparatus used to perform the exposure, a proximity exposure apparatus, which exposes the silhouette of a mask pattern onto a substrate by arranging the mask in the proximity of the substrate, and a projection exposure apparatus, which arranges an imaging optical system between the mask and the substrate and exposes the image of a mask pattern onto a substrate, are mainly used.